February, '13] BISHOPP: STABLE FLY ' 125 



Artificial Control 



Destruction of Breeding Places. Since straw stacks have 

 been found to be the principal breeding places of this insect in the grain 

 growing belt, attention should be given to the care of straw as the 

 most important step in control. In general, it is the practice through- 

 out the grain belt for farmers to stack the straw by the use of self- 

 stacking threshing machines. After the threshing is done no attention 

 is paid to the care of the stack until a year or two after when in some 

 instances it is burned, in other cases the new straw is stacked on top 

 of the old piles. These practices are bad, not only on account of the 

 breeding of Stomoxys and other flies, but the full manurial value of the 

 straw is not secured and a considerable amount of valuable land is 

 occupied continuously by the large and often scattered stacks of 

 straw. In many cases it has been found that these stacks occupy 

 as much as a hundred yards square of tillable soil. On account of the 

 fact that straw is depended upon by many farmers to supplement their 

 other food supply for live stock during the winter, a general recom- 

 mendation to burn the stacks immediately after threshing is not 

 practicable. All the straw which is not required for winter feed for 

 cattle should be destroyed by burning or scattered over the land soon 

 after threshing and plowed under subsequently. Oat straw is usually 

 used for feeding purposes. It should be remembered that this also 

 forms the most favorable breeding medium for Stomoxys. It is 

 therefore recommended that the straw for feeding and bedding pur- 

 poses be baled and stored under cover. Where this is not practicable 

 the stacks should be rounded up so as to make the top largely rain 

 proof and the sides almost vertical. 



It should be borne in mind that under conditions similar to those 

 which prevailed during the summer of 1912 the straw stacks are largely 

 rendered unfit for food owing to the thorough wetting by August rains, 

 and are, therefore, of little value except for fertilizing purposes. In 

 such instances where the flies are already breeding in uncared-for 

 stacks they should be promptly burned or scattered. If the scattering 

 is done thoroughly the exposure of the straw to drying and light will 

 effectually stop the breeding of the flies. 



Where headers instead of binders are used the straw question is less 

 important as most of the straw is left in the field and later plowed 

 under. The destruction of the chaff and the short straw taken by 

 headers can readily be disposed of as indicated above. 



The use of poisons is not advisable as quantities sufficient to per- 

 ^meate the stacks and kill the larvae would be very dangerous to stock 



